how to generate random number or Alphabetic in java

apache.commons-lang3

compile group: 'org.apache.commons', name: 'commons-lang3', version: '3.4'

tutorial - generate sample code:

//[a-zA-Z] -> RandomStringUtils.randomAlphabetic(count)
//[0-9] -> RandomStringUtils.randomNumeric(count)
//[a-zA-Z0-9] -> RandomStringUtils.randomAlphanumeric(count)

String.format("%s-%s-%s", RandomStringUtils.randomAlphabetic(5),
                RandomStringUtils.randomNumeric(5),
                RandomStringUtils.randomAlphanumeric(5)).toUpperCase();

output: OYNED-01202-GW424